Tutorial on how to create a Sticky Back to Top Button

I am enthused about working in Justinmind but having difficulty figuring out a lot of interactive elements needed that would make spending hours and hours creating a prototype worth it. Time is money! I am hoping there is not an initial steep learning curve.

Can someone send me a tutorial on how to create a Sticky Back to Top Button? I can't be the only one who needs this or has not figured out the magic process. Your help is much appreciated!